Pyro/piezoelectric effects are thought as essential ways to modulate photoresponses of optoelectronic devices, but the pyro/piezoelectric materials usually function as photoactive or fundamental band matching layers. In this manuscript, a Cu(In,Ga)Se 2 (CIGS) multilayer heterojunction of Glass/Mo/ CIGS/CdS/ZnO nanowire/ITO is prepared as a self-powered photodetector (PD). The PD exhibits excellent performances in 405 to 1064 nm with maximum responsivity (R) of 0.455 A W −1 , and detectivity (D) of 7.22 × 10 11 Jones at zero bias. More importantly, the temperature variation-induced pyroelectric field in the non-photoactive ZnO layer is demonstrated to facilitate the transport of carriers. After introducing the pyroelectric effect, the responsivity (R) and detectivity (D) are largely increased to 4.92 A W −1 and 7.81 × 10 12 Jones, respectively, and an ultrafast response time of 67.13/78.57 µs is obtained. Meanwhile, the response wavelength is extended to 1550 nm, which is far beyond the spectral limitation of the heterojunction. Besides, the piezoelectric effect of the ZnO nanowire can further optimize the band alignment and then boost the photovoltaic and pyroelectric responses. Owning to the favorable three-synergistic mechanisms, the best R of 7.22 A W −1 and D of 1.17 × 10 13 Jones are observed, which are enhanced by 1586.8% and 1620.5%, respectively, and the response time is also shortened to 50.17/60.65 µs.

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Bi2Se3, as a novel 3D topological insulator (TI), is expected to be a strong candidate for next-generation optoelectronic devices due to its intriguing optical and electrical properties. In this study, a series of Bi2Se3 films with different thicknesses of 5–40 nm were successfully prepared on planar-Si substrates and developed as self-powered light position-sensitive detectors (PSDs) by introducing lateral photovoltaic effect (LPE). It is demonstrated that the Bi2Se3/planar-Si heterojunction shows a broad-band response range of 450–1064 nm, and the LPE response is strongly dependent on the Bi2Se3 layer thickness, which can be mainly attributed to the thickness-modulated longitudinal carrier separation and transport. The 15 nm thick PSD shows the best performance with a position sensitivity of up to 89.7 mV/mm, a nonlinearity of lower than 7%, and response time as fast as 62.6/49.4 μs. Moreover, to further enhance the LPE response, a novel Bi2Se3/pyramid-Si heterojunction is built by constructing a nanopyramid structure for the Si substrate. Owing to the improvement of the light absorption capability in the heterojunction, the position sensitivity is largely boosted up to 178.9 mV/mm, which gets an increment of 199% as compared with that of the Bi2Se3/planar-Si heterojunction device. At the same time, the nonlinearity is still kept within 10% as well due to the excellent conduction property of the Bi2Se3 film. In addition, an ultrafast response speed of 173/97.4 μs is also achieved in the newly proposed PSD with excellent stability and reproducibility. This result not only demonstrates the great potential of TIs in PSD but also provides a promising approach for tuning its performance.

Sb2Se3 exhibits fascinating optical and electrical properties owing to its unique one-dimensional crystal structure. In this study, a Sb2Se3-nanorod/CdS core-shell heterostructure was successfully constructed, and the lateral photovoltaic effect (LPE), as well as the lateral photocurrent and photoresistance effects, were first studied. The measurements indicate that this heterojunction exhibits excellent lateral photoelectric performance in a broad range of 405-1064 nm with the best position sensitivities (PSs) of 525.9 mV/mm, 79.1 µA/mm, and 25.6 kΩ/mm for the lateral photovoltage, photocurrent, and photoresistance, respectively, while the nonlinearity is maintained below 7%, demonstrating its great potential in a novel high-performance multifunctional position sensitive detector (PSD). Moreover, this PSD could work well at different frequencies with good stability and repeatability, and the rise and fall times were deduced to be 48 and 180 µs, respectively. Besides, large linear working distances are achieved in this heterojunction PSD, and the PS can still reach 75.5 mV/mm even at an ultra-large working distance of 9 mm. These outstanding performances can be attributed to the high-quality Sb2Se3 nanorod arrays and the fast charge-carrier separation and transport properties of this core-shell heterojunction. This study provides important ideas for developing high-performance, broadband, large working distances, and ultrafast multifunctional PSDs based on the new core-shell heterostructure.

In order to explore the influence of different lengths of hydrophobic carbon chains on the diffusion characteristics of surfactants on the surface of anthracite, six linear alkyl benzene sulfonates with different hydrophobic carbon chain lengths were selected (mC, m = 8, 10, 12, 14, 16, 18; m represents the numbers of carbon atoms in the hydrophobic carbon chain), and molecular dynamics (MD) simulations were adopted. Models of surfactant-anthracite, surfactant-graphite layer, and water-surfactant-anthracite were constructed. After analyzing a series of properties such as adsorption energy, diffusion coefficient, radial distribution function (RDF), and hydrophobic tail order parameters, it was found that 12C had the highest adsorption strength on the surface of anthracite; the reason was that 12C had the highest degree of aggregation near the oxygen-containing functional groups on the surface of anthracite. Further studies had found that the hydrophobic tail chain of 12C had the strongest isotropy. The study fills the gap in the systematic study of the diffusion characteristics of linear alkylbenzene sulfonates (LAS) with different chain lengths on the surface of anthracite, enriches and develops the basic theory of coal wettability, and also provides technical ideas for the design of new surfactants and new dust suppression agents.